Molding is a commonly used technique to protect integrated circuit devices from the damage of external environments. In a typical molding process, a molding compound is dispensed on a device that is to be molded. A mold is used to confine and shape the molding compound. The molding compound is then cured and solidified, followed by the removal of the mold from the molding compound.
When large integrated circuit components (such as wafers) are molded, air bubbles may be trapped in the molding compound. This is often caused by the high viscosity of the molding compound, which fails to flow to all of the regions that are to be molded. Stresses may be generated in the molded packages due to the existence of air bubbles when atmospheric pressure changes. For example, after a device is molded, some process steps may need to be performed in vacuum environments. These process steps include, for example, Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), and the like. The air bubbles causes stresses in the molded packages due to the pressure differences inside and outside the air bubbles. The stresses may cause thin wafers to break. In addition, the air bubbles may also result in a high degree of warpage in the molded packages.